Sanding generates dust and the more vigorous the removal of material from a target of abrasion, the greater the amounts of dust generated. This dust is first airborne and can remain in the air for some time before settling. While airborne the dust is a hazard to people and requires filtering masks and other protective gear to be worn by workers and anyone else in the environment. Dust settling out of the air onto whatever surface it may drift or be blown requires laborious and time consuming effort to clean up and remove for disposal. Even if a room is sealed and surfaces protected with drop cloths or the like, the dust which falls on the workers, and the dust raised in the folding or rolling up of the drop cloths, etc., is, to some degree at the very least, lifted into the air again to settle again. This in turn requires repeated sweeping, scrubbing, and dusting of all furniture and of all surfaces both horizontal and vertical (walls, ceilings, floors) to finally clean an area.
Various attempts have been made to minimize the dust entering the general area and thus minimizing the amount of dust which will settle out of the air. These attempts have consisted of attempting to pull abraded debris and finer particulate dust by means of a vacuum stream after the dust has been generated by the abrading. In some designs of prior art grooves are cut into a rigid tool holding an abrasive screen. The grooves are cut in an attempt to channel debris to an exit after the dust's production. Some dust always escapes from the borders of the tool and the rigidity of the tool creates other problems: Suction between the rigid plate and the surface to be abraded can cause the tool to hesitate and to stick to that surface and the rigidity of the tool can contribute to gouging the surface to be abraded. Additional appliances have been offered to collect the dust which escapes from the borders of these devices, such as skirts or shrouds surrounding the tool. These devices add to the weight of the device and still fail to collect all the debris. In another offering the sides of the tool are raised to provide vacuum holes on the sides as well as the face of the device. The abrading material is held above the tool by a porous support but the channeling remains inefficient by relying again on the channeling grooves to exhaust the particulate dust and again, the weight of the device is increased.
All of the above devices are directed to sanding only planar surfaces. This restricts the use of the tool to such situations where the target surface is not only flat but of sufficient area to accommodate the dimensions of the tool. All of the above devices can be urged against a target surface at only one level of pressure, thus precluding a choice between a light sanding and hard planing away of unwanted material.
Devices of this sort all require replaceable abrasive screens. Wear and tear and general fatigue of these screens is exacerbated when the screen is pressed against the wall by the rigid face of the device holding the screen. When back and forth movement is part of the sanding process the fatigue is increased. Another factor contributing to the fatigue is the mechanism by which the screens are attached to the device. Generally, the screen is affixed to the tool by clamping the end edges of the screen between the jaws of a spring loaded metal clamp or forcing the ends of the screen into a groove cut in hard rubber, or by holding the ends of the screen in position around the face of the tool and securing it there by clamps on either side of the tool which are tightened by turning wing nuts to close the clamps. The edges of all these clamping mechanisms create blades which can tear the abrasive screen. All of these methods of fastening are also difficult and cumbersome and therefore time consuming.
These and other examples of similar prior art are described in U.S. Pat. No. 5,283,988 of Brown, U.S. Pat. No. 5,440,616 of Harrington et al., U.S. Pat. No. 4,071,981 of Champayne, U.S. Pat. No. 4,697,389 of Romine, U.S. Pat. No. 5,245,797 of Milkie, U.S. Pat. No. 5,540,616 of Thayer, U.S. Pat. No. 4,765,099 of Tanner, U.S. Pat. No. 4,937,984 of Taranto, U.S. Pat. No. 4,680,895 of Roestenberg, and U.S. Pat. No. 4,799,385 of Hulsing et al.
However, the aforementioned devices do not describe a dustless sander wherein the head of the sander, an abrasive screen supported by a malleable, air permeable cushion, projects outwardly from the body of the sander supported by a flat funnel-like platform rotating on the end of a hollow shaft, including a plurality of containers which are stacked one within the other and wherein the two containers embrace and swivel with the platform around the hollow shaft, wherein further a vacuumed stream of air draws debris not only from the working surface but also from the peripherally surrounding area before the debris escapes into the atmosphere.